- MOLA-2 is actually called the Mars
Orbiter Laser Altimeter (even though the logo says "Orbital"; the name has changed a couple times). This is because the spacecraft is no longer the Mars Observer, but rather the Mars Global Surveyor. Of course, this has nothing to do with the mechanical structure, but it is a factoid.
- MOLA Materials List
Material Density (lb/cubic inch) Young's Modulus (psi) Shear Modulus (psi) Poisson's Ratio Thermal Expansion (in/in/F) MOLA Components Aluminum 6061-T651 0.098 9900000 3800000 0.33 0.00001265 Various Structural Honeycomb Panel 0.0042 468000 ~ 0.33 0.00001265 Support Panel Magnesium ZK60A 0.065967 6500000 2400000 0.35 0.0000134 G-10 Epoxy Glass 0.068 2000000 892857 0.12 0.000032 Circuit Boards Stainless Steel 303 0.286 28000000 ~ 0.27 0.0000096 Titanium 6Al-4V Plate 0.16 16000000 6200000 0.31 0.0000049 Beryllium S200-F 0.067 44000000 20370370 0.08 0.0000102 Beryllium-SR-200E 0.067 44000000 20754717 0.06 ~ Beryllium I220 B 0.067 44000000 20370370 0.08 ~ AISI 4340 Steel 0.02 29000000 10984848 0.32 0.0000066 Fused Silica 0.14361 10000000 3759398 0.33 0.0000234 Unobtainium 0 2000000 892857 0.12 0.000032 Detector Boards Unobtainium is obviously not an actual material. Often we need specific properties of some materials without other properties being present. In this case, I wanted some of the strength properties of G-10, but not the mass. Hence, Unobtanium.
- MOLA 2 FEM Stats
FEM Component Quantity Nodes 8866 Elements 10204 Materials 15 Properties 168 Model Extents X Y Z -15.789 -16.1685 -3.25 15.789 12.0443 19.4265 The model extents are taken from the model origin, which is located on the optical axis at the support panel midplane (as shown in the exploded view).
- Mass Properties of the standard MOLA Model.
The Origin is located on the optical axis at the support panel midplane (as shown in the exploded view).Center of Gravity (from origin) Mass (lbs) X (in) Y (in) Z (in) Structural 41.88974 -0.190483 -2.872827 4.443094 NonStructural 15.74856 -0.230001 -9.189502 3.198256 Total Mass 57.6383 -0.20128 -4.598737 4.102966 Mass Moments of Inertia Inertias about the Origin Ixx 6033.54 Ixy 11.7679 Iyy 3833.677 Iyz -692.0615 Izz 6269.474 Izx -82.73241 Inertias about Center of Gravity Ixx 3830.372 Ixy -41.58405 Iyy 2849.489 Iyz 395.4844 Izz 5038.693 Izx -35.13199 - UAI/NASTRAN Grid Point Weight Generator Table for the MOLA 2 FEM.
G R I D P O I N T W E I G H T A N D B A L A N C E S U M M A R Y REFERENCE POINT = 0 RIGID BODY MASS MATRIX AT REFERENCE POINT IN BASIC COORDINATE SYSTEM *** *** * 5.763811E+01 0.000000E+00 0.000000E+00 0.000000E+00 2.364870E+02 2.650634E+02 * * 0.000000E+00 5.763811E+01 0.000000E+00 -2.364870E+02 0.000000E+00 -1.160180E+01 * * 0.000000E+00 0.000000E+00 5.763811E+01 -2.650634E+02 1.160180E+01 0.000000E+00 * * 0.000000E+00 -2.364870E+02 -2.650634E+02 6.030214E+03 -1.180784E+01 8.273367E+01 * * 2.364870E+02 0.000000E+00 1.160180E+01 -1.180784E+01 3.834166E+03 6.920634E+02 * * 2.650634E+02 -1.160180E+01 0.000000E+00 8.273367E+01 6.920634E+02 6.278718E+03 * *** *** TRANSFORMATION MATRIX, BASIC TO PRINCIPAL MASS SYSTEM *** *** * 1.000000E+00 0.000000E+00 0.000000E+00 * * 0.000000E+00 1.000000E+00 0.000000E+00 * * 0.000000E+00 0.000000E+00 1.000000E+00 * *** *** CENTER OF GRAVITY SUMMARY DIRECTION MASS AXIS SYSTEM MASS X-C.G. Y-C.G. Z-C.G. X 5.763811E+01 0.000000E+00 -4.598752E+00 4.102962E+00 Y 5.763811E+01 -2.012869E-01 0.000000E+00 4.102962E+00 Z 5.763811E+01 -2.012869E-01 -4.598752E+00 0.000000E+00 INERTIA MATRIX IN THE PRINCIPAL MASS SYSTEM *** *** * 3.840956E+03 4.154594E+01 3.513194E+01 * * 4.154594E+01 2.861534E+03 -3.954818E+02 * * 3.513194E+01 -3.954818E+02 5.057421E+03 * *** *** PRINCIPAL MOMENTS OF INERTIA *** *** * 5.127064E+03 * * 2.790378E+03 * * 3.842469E+03 * *** *** TRANSFORMATION MATRIX, PRINCIPAL INERTIA TO PRINCIPAL MASS *** *** * 2.136337E-02 4.465263E-02 9.987742E-01 * * -1.715449E-01 -9.840227E-01 4.766241E-02 * * 9.849446E-01 -1.723529E-01 -1.336210E-02 * *** ***
- Mass Properties of the Dynamics MOLA Model.
The Origin is located on the optical axis where the instrument's feet attach to the spacecraft. This coordinate system is used for dynamics analyses. This information is not to be confused with properties from the standard FEM given above.Center of Gravity (from alternate origin) Mass (lbs) X (in) Y (in) Z (in) Structural 44.64165 -0.178741 -2.976193 7.466716 NonStructural 13.70766 -0.264245 -9.66845 6.924437 Total Mass 58.34931 -0.198828 -4.548365 7.339321 Mass Moments of Inertia Inertias about the Origin Ixx 8200.813 Ixy 11.7679 Iyy 6000.951 Iyz -1554.592 Izz 62969.474 Izx -120.4372 Inertias about Center of Gravity Ixx 3850.682 Ixy -40.9998 Iyy 2855.622 Iyz 393.2197 Izz 5060.058 Izx -35.29028
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This page is maintained by Ryan Simmons, at Ryan.Simmons@nasa.gov.This page was last updated on April 10, 1996.